Speaker cube



FIG. 1 is a perspective view of a speaker cube, shown in environmental use in enlarged scale, showing my new design;

FIG. 2 is a front view thereof;

FIG. 3 is a back view thereof;

FIG. 4 is a first side view thereof;

FIG. 5 is a second side view thereof;

FIG. 6 is a top plan view thereof; and,

FIG. 7 is a bottom plan view thereof.

The broken line portions are included to show unclaimed subject matter only and form no part of the claimed design. 

CLAIM The ornamental design for a speaker cube, as shown and described. 